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• Hydrocyclone-induced pretreatment for sludge disintegration was first proposed. • Efficient SCOD release was achieved at specific energy 0.18 W/g TS by hydrocyclone. • Combined pretreatment presents higher SCOD release, VFAs and CH 4 production. • Net profit of 131.73 USD/t TS was achieved for optimal combined pretreated sample. Hydrocyclone-induced pretreatment was first proposed for sludge disintegration to address excess sludge and to be served as a means of sustainable energy production. The effects of hydrocyclone disintegration alone and combination of hydrocyclone and alkaline pretreatments on sludge solubilization followed by anaerobic digestion were investigated. Initially, the flocs were disrupted through hydrocyclone at an optimal specific energy input of 0.18 W/g TS, with 2142 mg/L soluble chemical oxygen demand (SCOD) release. The hydrocyclone induced alkaline pretreatment in different sequence was investigated subsequently, and a maximal SCOD release of 4409 mg/L was observed in combination IV, which included hydrocyclone treatment throughout and alkaline treatment from 50th min to 80th min. Mechanisms of organics release via hydrocyclone-induced sludge pretreatment were also explored, and the sludge disintegration was attributed to its anisotropic flow field as well as common actions of sheared shedding and rotation desorption. The biodegradability analysis exhibited that the optimal combined pretreated sludge also exhibited 23.75% higher levels of VFA accumulation to 1017 mg/L, 32.38% more methane production to 134.29 mL CH 4 /g TS and 5.9% more VSS reduction to 29.3% relative to the hydrocyclone pretreated sludge. An economic of optimal combined sludge pretreatment offers a positive net profit of 130.42 USD/ton of TS, was assessed to be a cost-effective process. [ABSTRACT FROM AUTHOR]

Combining more than one processes in one-step is an effective approach for economical, ecological and efficient processing of textiles. The most commonly used alpha-amylase enzyme, suitable for desizing woven fabrics, is not compatible for combined desizing-scouring-bleaching process in one step due to lack of stability under high temperature and alkaline condition in the combined process. The aim of this study was to use a novel, non-enzymatic desizer, which is stable under high alkalinity and temperature condition in the combined process. The lab trials showed the effectiveness of non-enzymatic desizer for one-step pretreatment of polyester/cotton blended fabrics. After successful lab trials, the proposed one-step process for combined desizing-scouring-bleaching on polyester/cotton blended fabrics was optimized for industrial-scale application. The concentration parameters for hydrogen peroxide, sodium hydroxide and the desizer were optimized with the help of central composite experimental design (CCD) of response surface methodology. The results obtained in one-step pretreatment method, in terms of the physical properties of the treated fabrics, were comparable with the results obtained by separate desizing, scouring and bleaching processes carried out on the identical fabric. However, the proposed one-step pretreatment process is much more advantageous with respect to saving in chemicals, water and energy as well as reduction in the process time. [ABSTRACT FROM AUTHOR]

Pretreatment was the essential step for industrial application of lignocellulosic biomass. Combination of steam explosion and fungal treatment was conducted, and synergistic mechanism of the combined pretreatment was evaluated in terms of pore size distribution, crystallinity index, chemical compositions and enzymatic hydrolysis. The results showed that steam explosion destroyed the rigid structure of corn stalk, increased pore size and porosity, and exposed crystalline component of cellulose. Steam explosion broke the lignin-carbohydrate-complex structure of lignocellulosic biomass and facilitated the fungal treatment.Phellinus baumii could selectively degrade 34.7% and 36.58% of lignin for 1.4 MPa and 1.7 MPa steam-exploded corn stalk, respectively. As a result, the highest glucose yield of corn stalk pretreated by the condition of 1.7 MPa steam explosion associated with 21 d P. baumii reached 313.31 g kg-1, which was 2.88 and 1.32 times higher than that of the untreated corn stalk and the 1.7 MPa steam-exploded corn stalk, respectively. The combined pretreatment enhanced the enzymatic hydrolysis, which was a promising technology that might be explored as alternative to the existing pretreatment. [ABSTRACT FROM AUTHOR]

The synergetic effect of ultrafine grinding coupled with the incorporation of an appropriate amount of nanomaterials (NMs) on biohydrogen (bioH 2) production from corn stover (CS) was studied. The changes in the physicochemical and optical characteristics of CS pretreated with various ultrafine grinding times were comprehensively studied. High-quality SnO 2 NMs with high defect concentrations (e.g., oxygen vacancies (OVs)) were successfully synthesised. The physio-optical structures of pretreated CS and synthesised NMs were analysed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy, and diffuse reflectance spectroscopy. SEM measurements confirmed that the morphology of the CS changed with the increase in grinding time and the particle size was reduced to the submicron range with increased surface roughness. The biomass particle size changed considerably from micron to submicron with an increase in grinding time. The intensities of the diffracted peak 22° decreased and the full width at half maximum increased with the increase in grinding time, which confirmed the considerable modification of biomass crystalline structure. The SEM analysis revealed that the synthesised SnO 2 NMs were spherical in nature with a uniform size distribution. XRD analysis confirmed that the synthesised NMs had a stable rutile structure without any secondary phases. Hydrogen production tests were performed by utilising a mixed consortium of photosynthetic bacteria HAU-M1 as the inoculum. Hydrogen production rates of 120, 123, and 145 mL/h were observed for samples pretreated with 2, 4, and 6 h of ultrafine grinding, respectively. Owing to the synergetic effect of ultrafine grinding and nanomaterial loading, the hydrogen production rate increased considerably to 143, 144, and 163 mL/h after 2, 4, and 6 h of ultrafine grinding and nanomaterial loadings of 200, 150, and 150 mg/L, respectively. The highest cumulative bioH 2 production of 425 mL was recorded after ultrafine grinding for 6 h and nanomaterial loading of 150 mg/L, 49% higher than that achieved with the standard sample (285 mL). Furthermore, the synergetic effect reduced not only the lag time (from 36 to 24 h) but also the amount of SnO 2 NMs loading required to achieve the highest hydrogen production rate (150 mg/L) as compared with the standard sample (200 mg/L). Our results highlight that an appropriate combination of pretreatments can present a potential roadmap to enhance bioH 2 production from lignocellulosic biomass, which can be a prospective sustainable energy supply. [Display omitted] • SEM images showed 6 h ultrafine grinding has particle size in the range of micron. • High quality SnO 2 NMs with size variation of 5–15 nm were fabricated. • Highest HPR of 163 mL/h was observed at 6 h of ultrafine grinding and 150 mg/L NMs. • In comparison to SS, the total bioH 2 yield is 49% higher with synergetic effect. • The synergetic effect helped to reduce the lag time (24 h from 36 h). [ABSTRACT FROM AUTHOR]

Biohydrogen production from sewage sludge through anaerobic fermentation is a cleaner production process. However, the complex sludge structure, especially the outer-layer extracellular polymeric substances, significantly restricts the utilization of available organics in the inner-layer sludge cells for hydrogen production. In view of this, this study firstly adopted a cation-binding agent, sodium citrate (SC), to strip the outer-layer extracellular polymeric substances from the sludge floc, followed by thermal disintegration of microbial cells, which aimed to promote the disintegration performance and biohydrogen productivity. The results showed that the sludge with the combined SC-Thermal pretreatment (0.3 g SC/g-SS + 121 °C for 30 min) achieved the maximum biohydrogen yield of 28.6 mL/g-VS added , which was 346.9%, 73.3% and 148.7% higher that of the control, sole SC pretreated system, and sole thermal pretreated system, respectively. The mechanism study revealed that the combined SC-Thermal pretreatment synergistically disintegrated the sludge floc and promoted the soluble organics content by 107.5 times. Meanwhile, the combined pretreatment also shortened the lag time of hydrogen formation, accelerated the hydrolysis, and improved the organics utilization, thus contributing to the improvement of hydrogen yield. The bacterial community analysis demonstrated that the combined pretreatment promoted the abundances of hydrolytic genera (Bacteroides , Proteocatella and Proteiniclasticum) and hydrogen-producing genera (Clostridium sensu stricto , Citrobacter , Paraclostridium and Escherichia-Shigella), which might be fundamentally responsible for the improvement of biohydrogen productivity. [Display omitted] • Combined sodium citrate-thermal pretreatment evidently disrupted the sludge flocs • Pretreatment promoted the SCOD content by 107.5 times and accelerated the hydrolysis • Pretreatment improved the bioH 2 yield by 346.9% and shortened the lag phase • Pretreated sludge exhibited the mixed acid type fermentation • Pretreatment improved the abundance of hydrogen-producing bacteria in the reactor [ABSTRACT FROM AUTHOR]

• The individual or dual effect of ultrasound/ozone pretreatment on microalgae were studied. • Ultrasound, released proteins to the aqueous phase and increased lipids viability. • Ozone, induced carbohydrates and phosphorus depolymerization. • Dual ultrasound and ozone intensified microalgae biocompounds fractionation. • Dual pretreatment reduced 95 % the solvent waste and 80 % the extraction time. This study applies individual and combined application of ultrasound and ozone pretreatments for the tandem recovery of microalgae biocompounds (lipids, proteins, and, carbohydrates) and phosphorus from Scenedesmus obliquus cultivated in wastewater. Results of individual application showed that ultrasound released protein to the aqueous phase (99 ± 3 %), and increased microalgal lipid viability from 11 to 90 ± 2 %. Whilst ozone pretreatment induced carbohydrate release to the aqueous phase 28 ± 1 %. Combined ultrasound and ozone pretreatment were studied in sequence mode. Ultrasound was first applied to release proteins and expose lipids, followed by ozone to induce carbohydrates and phosphorus release. The maximum yields of recovered lipids, proteins, carbohydrates and phosphorus by the combined pretreatment were 89 ± 1 %, 91 ± 8 %, 63 ± 1 %, and 75 ± 1 % respectively. In the dual pretreatment best experimental parameters applied for ultrasound were: biomass concentration of 25 g/L and applied energy of 200 kW h/kg dry biomass. Ozone pretreatment used 27 mg O 3 /L, contact time 25 min and pH of 11. The combined pretreatment intensified microalgae fractionation achieving high biocompounds and phosphorus recovery yields; reducing solvent waste by 95 % and extraction time by 90 %, in comparison to biocompounds extraction without pretreatment. [ABSTRACT FROM AUTHOR]